Bruce A. Werness

Altered surface and cyst epithelium of ovaries removed prophylactically from women with a family history of ovarian cancer.

Despite intensive investigation, the nature of epithelial ovarian cancer precursors remains controversial. Because women with a strong family history of ovarian cancer have a high probability of developing ovarian cancer themselves, ovaries removed prophylactically from such patients provide an opportunity to identify early neoplastic changes. Ovaries removed from 64 consecutive patients undergoing prophylactic oophorectomy and from 30 women with normal ovaries and no known family history of ovarian cancer were examined by light microscopy for a number of histopathologic features and by image cytometry for abnormalities of the cyst and surface epithelium. All analyses were performed without knowledge of the family history. Seven benign, but no tumors of low malignant potential or malignant epithelial tumors were found in the prophylactic oophorectomy group. There were more cortical inclusion cysts in the prophylactically removed than controls ovaries (P = .016), but no other architectural features differed between the two groups. No abnormalities were found in the surface or cyst epithelium in either group by light microscopy. In contrast, image analysis identified differences in the nuclei between the two groups, indicating that those from the surface epithelium of prophylactically removed ovaries were larger and contained more heterogeneously dense chromatin than those of controls, and that nuclei of the cyst epithelium had more irregular outlines. Ovarian epithelium from prophylactically removed ovaries exhibit abnormalities that are only identified by image analysis, and which might represent early preneoplastic changes. Such ovaries may be useful for identifying early molecular changes in ovarian cancer.

Histopathology, FIGO stage, and BRCA mutation status of ovarian cancers from the Gilda Radner Familial Ovarian Cancer Registry.

Studies of the histopathology of ovarian cancer arising in patients with germline mutations in BRCA1 or BRCA2 have shown inconsistent findings. We analyzed the large number of tumors from women enrolled in the Gilda Radner Familial Ovarian Cancer Registry for correlations between histopathology and BRCA mutation status. Histopathology slides and reports were reviewed for histology, grade, and stage for cancers of the ovary or peritoneum in 220 women from 126 Gilda Radner Familial Ovarian Cancer Registry families. At least one affected member of each family was analyzed for mutations in the BRCA1 and BRCA2 genes, and tumors from mutation-positive families were compared with those from mutation-negative families. Of 70 patients from 38 BRCA1-positive families, 69 had epithelial ovarian carcinoma and one had a dysgerminoma. Fifteen of 16 patients from nine BRCA2-positive families had epithelial ovarian cancer, and one had a primary peritoneal cancer. Of 134 patients from 79 BRCA-negative families, 118 had epithelial ovarian carcinoma, 11 had ovarian borderline tumors, three had nonepithelial tumors, and two had primary peritoneal carcinoma. There were fewer grade 1 (p < 0.001) and stage I (p = 0.005) cancers in patients from BRCA-positive families than in patients from BRCA-negative families. Neither mucinous nor borderline tumors were found in the BRCA-positive families. In conclusion, ovarian cancers arising in women from BRCA-positive families are more likely to be high-grade and have extraovarian spread than tumors arising in women from BRCA-negative families. Borderline and mucinous tumors do not appear to be part of the phenotype of families with germline mutations in the BRCA genes.

Histopathology of familial ovarian tumors in women from families with and without germline BRCA1 mutations

Breast cancers from patients with germline BRCA1 mutations show characteristic histopathologic features. However, similar studies of BRCA1-associated ovarian cancers have reported inconsistent findings. Interobserver differences in histopathologic classification are a significant source of variation, and most studies have obtained histopathologic information from pathology reports rather than from review of histopathology slides. We therefore reviewed the histopathology slides and pathology reports to determine histologic type, grade, and stage for cancers of the ovary or peritoneum in 217 women from 126 families enrolled in the Gilda Radner Familial Ovarian Cancer Registry. Peripheral blood DNA from at least 1 affected member of each family was analyzed for BRCA1 mutations, and tumors from BRCA1 mutation-positive families were compared with those from BRCA1-negative families. Of 66 patients from 36 BRCA1-positive families, 64 had ovarian carcinoma, 1 had an ovarian carcinoma in situ, and 1 had a dysgerminoma. Of 151 patients from 90 BRCA1-negative families, 135 had ovarian carcinoma, 10 had ovarian borderline tumors, 3 had ovarian sex cord/stromal tumors, and 3 had primary peritoneal carcinoma. There were fewer grade 1 (P <.001) and stage I (P =.10) cancers in patients from BRCA1-positive families than in patients from BRCA1-negative families. Neither mucinous nor borderline tumors were found in the BRCA1-positive families. Ovarian cancers arising in women from BRCA1-positive families are more likely to be high grade and nonmucinous than cancers arising in women from BRCA1-negative families. The absence of borderline tumors in patients from BRCA1-positive families adds to accumulating evidence that BRCA1 mutations do not play a role in the development of these tumors. HUM PATHOL 31:1420-1424.

Malignant peripheral nerve sheath tumors of the head and neck: Analysis of prognostic factors

Malignant peripheral nerve sheath tumors of the head and neck region are uncommon and may be associated with neurofibromatosis or occur in a sporadic manner. This is a retrospective review of 17 patients with these tumors who were treated at a single institution. Analysis of clinical and pathologic factors that influenced outcome was performed. There were 9 men and 8 women. Seven patients had a history of neurofibromatosis. Radiotherapy was implicated as a possible etiologic factor in 4 patients. The neck was the most frequently involved site. Overall survival at 5 years was 52%. Survival was improved for women and for patients with low-grade tumors. Age, tumor site, and size had no impact on survival. Survival was worse for patients with neurofibromatosis than for those with the sporadic form of the disease (P = 0.02). Survival was calculated by the method of Kaplan and Meier. The significance of such results was based on results of the log rank test. Local recurrence correlated with tumor size and resection margin status. No local recurrences occurred in those patients who had negative margins of resection and received adjuvant radiotherapy. Tumor grade was predictive of the development of distant metastases. Negative margins of resection are essential for obtaining local control, and the addition of adjuvant radiotherapy may be beneficial in this group. Salvage surgery for local recurrence is possible in some patients.

Mutations in BRCA1 from Fixed, Paraffin-Embedded Tissue Can Be Artifacts of Preservation

DNA isolated from paraffin-embedded tissues has been used for analysis of DNA alterations in disease states. Use of archival tissue can expedite the gathering of large numbers of specimens from rare disease subtypes that would take years to accumulate prospectively. Therefore, archival tissues from 70 ovarian cancer cases diagnosed before or at age 40 were retrieved for analysis of BRCA1 mutations. DNA was isolated from paraffin-embedded tissue of 70 ovarian cancer cases diagnosed before or at age 40. BRCA1 mutation analysis was conducted by single-strand conformation polymorphism analysis and DNA sequencing. Fifty-eight BRCA1 mutations were found in 34 of the 70 ovarian cancer cases. Twenty-two cases had one mutation each and 12 cases had multiple mutations. Multiple mutations found in histologically normal tissue of 2 cases were not present in matched tumor tissue. For another case, DNA from two separate blocks of normal tissue contained different mutations. These observations were anomalous and suggested that mutations detected in fixed tissues may be artifacts of tissue preservation and not present in the original unfixed tissues. To test this suggestion, blood was obtained from 2 patients for whom mutations were found in fixed, normal tissue. DNA from their unfixed lymphocytes did not contain the mutations found in fixed normal tissue. Thus, mutations found in fixed, paraffin-embedded tissues can be artifacts of tissue preservation. The reliability of DNA sequence data derived from such tissues must be questioned in the absence of corroborating data from unfixed tissues. This severely limits the use of fixed tissues as a source of DNA for retrospective research and for clinical genetic testing in families for which a disease-affected member is not alive.

Correlation of TP53 Mutations and p53 Expression in Ovarian Tumors

To characterize the involvement of the TP53 tumor suppressor gene in ovarian cancer, mutation analysis of exons 2-11 of TP53 and immunodetection of its protein product, p53, were done in 48 ovarian tumors. Normally, p53 is not immunodetectable. Missense TP53 mutations have been reported to result in p53 accumulation and detection, but mutations generating premature stop codons have not. Mutations were identified in 19 of 41 malignant tumors but not in 5 benign tumors and 2 tumors of low malignant potential. Fifteen of the 19 tumors with mutations also stained positively by immunohistochemistry or Western blot or both. They included 11 missense mutations, 1 in-frame duplication (474ins6), and 3 frameshift mutations generating premature stop codons. The three tumors with frameshifts also had a wild-type TP53 allele and displayed normal size but not truncated p53 by Western blot. This indicates that these tumors express wild-type p53. The significance of TP53 mutations in the development of the three tumors is questionable unless there is a mechanism for inactivating wild-type p53. Nine of the 19 mutations found here, including the 3 frameshifts, were previously not reported in ovarian cancer. Thirteen of the 19 mutations were single nucleotide substitutions with 6 transitions and 7 transversions. The ratio of transversions to transitions (1.2) was different from literature reports (0.5) (P < 0.01). Thus, the spectrum of TP53 mutations in our study differed from other ovarian tumor reports. This difference may be due to population-based differences in the molecular epidemiology of TP53 mutations.

Familial ovarian cancer and early ovarian cancer: biologic, pathologic, and clinical features.

Women with ovarian cancer have poor overall survival rates, largely because the disease is so often diagnosed at an advanced, less curable stage. Because women with early ovarian cancer experience good survival rates, there is great interest in the study and detection of early disease. Familial ovarian cancer has been relevant to the study of early ovarian cancer in two different ways. First, women from ovarian cancer families often undergo prophylactic oophorectomy to prevent development of this disease. These ovaries have been studied for pathologic or molecular features that might represent early preinvasive disease. Second, screening tests to detect presymptomatic ovarian cancer have selectively targeted this population because of the increased positive predictive value of these tests in this population. A review of the clinical, pathologic, epidemiologic, and molecular biologic aspects of familial ovarian cancer provides a background to facilitate understanding these issues.

Expression of the p53 induced tumor suppressor p21waf1/cip1 in ovarian carcinomas: correlation with p53 and Ki-67 immunohistochemistry.

SummaryMutations of the p53 gene are the most common genetic alteration in malignant human tumors, including ovarian carcinomas of surface epithelial origin. A cyclin-dependent kinase inhibitor, p21waf1/cip1, is thought to be an important mediator of p53-induced cell cycle arrest. Although numerous studies have reported p53 expression and mutation in ovarian tumors, none have correlated p53 expression with that of its downstream effector, p21waf1/cip1. We studied p53 and p21waf1/cip1 expression by immunohistochemistry in 44 ovarian carcinomas of different histologic types and correlated these findings with each other and with proliferation as measured by expression of the Ki-67 nuclear antigen. Fifty percent of tumors expressed p53, whereas 34% expressed p21waf1/cip1. Clear cell carcinomas expressed p21waf1/cip1 significantly more often than other histologic types, and tumors with squamous differentiation showed higher p21waf1/cip1 expression in these areas. There was no correlation of p21waf1/cip1 expression with p53 expression, p53 mutation, or Ki-67 expression, p21waf1/cip1 appears to be induced independently of p53 in these tumors and may be associated with differentiation rather than proliferation.

Mutation analysis of BRCA1, TP53, and KRAS2 in ovarian and related pelvic tumors

Cancer may be viewed as a genetic disease resulting from critical mutations that disrupt normal cell growth. To characterize the involvement of the BRCA1 and TP53 tumor suppressor genes and of the KRAS2 protooncogene in gynecologic cancer, mutation analysis of these genes was conducted in pelvic tumors of 85 patients that included 49 epithelial ovarian carcinoma cases. The 85 pelvic tumors contained 5 tumors with BRCA1 mutations, 33 with TP53 mutations, and 1 with a KRAS2 mutation. Each of the BRCA1 and KRAS2 mutations, and 25 of the TP53 mutations, were in ovarian carcinomas. Four of the BRCA1 mutations were germline and 1 was somatic. The 4 patients with germline BRCA1 mutations had an early age of disease onset (33-48 years) relative to the mean age of onset (58 years) of all 49 ovarian carcinoma patients, and 3 of these 4 patients had a family history of ovarian or breast cancer. None of the 4 tumors with germline BRCA1 mutations had a KRAS2 mutation or a TP53 mutation, despite a 51% frequency of TP53 mutations in the 49 ovarian carcinomas. Three of the 4 tumors with germline BRCA1 mutations retained a wild-type BRCA1 allele. The tumor with the somatic BRCA1 mutation contained a TP53 mutation and had no evidence for wild-type BRCA1 and TP53 alleles. These data suggest that both BRCA1 and TP53 were inactivated in 1 of 49 ovarian carcinomas. Moreover, mutational inactivation of both BRCA1 and TP53 did not occur in 4 tumors with a germline BRCA1 mutation. It has been proposed that tumorigenesis in cells with a heterozygous BRCA1 mutation requires inactivation of the wild-type BRCA1 and TP53 alleles, which results in genomic instability and acquisition of mutations in protooncogenes. Clearly, mutational inactivation of TP53 and the wild-type BRCA1 allele in ovarian tumors with a heterozygous, germline BRCA1 mutation is not an absolute requirement for tumor formation. It is possible that these alleles may be inactivated by nonmutational mechanisms or that other tumor formation pathways exist.

Tumor of the broad ligament in von Hippel-Lindau disease of probable mullerian origin

A rare neoplasm seen in women with von Hippel-Lindau disease is the papillary cystadenoma of the broad ligament, only three cases of which have been reported. All three exhibited characteristic histologic features identical to those of epididymal tumors that occur in affected patients, and were presumed to be of wolffian origin. This is the case of a broad ligament tumor in a woman with von Hippel-Lindau disease that had features more consistent with a mullerian rather than wolffian origin. This is the first report of a broad ligament tumor of probable mullerian origin in von Hippel-Lindau disease.